The purposes of the Cell Line Characterization Core facility are: 1) To provide investigators of the STPPG with well-characterized cell lines derived from solid tumors of pediatric patients; 2) to establish, on a limited basis, cell lines that are not currently available from tumors of pediatric patients; 3) to maintain a data base that will include, but will not be limited to, oncogene and tumor suppressor genes expressed by each cell line and DNA fingerprinting for consistent identification of each cell line; 4) To provide bulk culture for establishment of xenografts; and 5) To amplify and provide characterized adenovirus to in vitro and in vivo use in the outlined projects.